Manual Pages for UNIX Darwin command on man IO::Socket

IO::Socket(3pm) Perl Programmers Reference Guide IO::Socket(3pm)

NAME

IO::Socket - Object interface to socket communications

SYNOPSIS

use IO::Socket;

DESCRIPTION

"IO::Socket" provides an object interface to creating and using sock-

ets. It is built upon the IO::Handle interface and inherits all the methods defined by IO::Handle.

"IO::Socket" only defines methods for those operations which are common

to all types of socket. Operations which are specified to a socket in a

particular domain have methods defined in sub classes of "IO::Socket"

"IO::Socket" will export all functions (and constants) defined by

Socket. CCOONNSSTTRRUUCCTTOORR new ( [ARGS] )

Creates an "IO::Socket", which is a reference to a newly created

symbol (see the "Symbol" package). "new" optionally takes argu-

ments, these arguments are in key-value pairs. "new" only looks

for one key "Domain" which tells new which domain the socket will be in. All other arguments will be passed to the configuration method of the package for that domain, See below.

NOTE NOTE NOTE NOTE NOTE NOTE NOTE NOTE NOTE NOTE NOTE NOTE

As of VERSION 1.18 all IO::Socket objects have autoflush turned on

by default. This was not the case with earlier releases.

NOTE NOTE NOTE NOTE NOTE NOTE NOTE NOTE NOTE NOTE NOTE NOTE

MMEETTHHOODDSS

See perlfunc for complete descriptions of each of the following sup-

ported "IO::Socket" methods, which are just front ends for the corre-

sponding built-in functions:

socket socketpair bind listen accept send recv peername (getpeername) sockname (getsockname) shutdown Some methods take slightly different arguments to those defined in perlfunc in attempt to make the interface more flexible. These are accept([PKG]) perform the system call "accept" on the socket and return a new object. The new object will be created in the same class as the listen socket, unless "PKG" is specified. This object can be used to communicate with the client that was trying to connect.

In a scalar context the new socket is returned, or undef upon fail-

ure. In a list context a two-element array is returned containing

the new socket and the peer address; the list will be empty upon failure. The timeout in the [PKG] can be specified as zero to effect a "poll", but you shouldn't do that because a new IO::Select object will be created behind the scenes just to do the single poll. This is horrendously inefficient. Use rather true select() with a zero

timeout on the handle, or non-blocking IO.

socketpair(DOMAIN, TYPE, PROTOCOL) Call "socketpair" and return a list of two sockets created, or an empty list on failure. Additional methods that are provided are: atmark True if the socket is currently positioned at the urgent data mark, false otherwise.

use IO::Socket;

my $sock = IO::Socket::INET->new('someserver');

$sock->read($data, 1024) until $sock->atmark;

Note: this is a reasonably new addition to the family of socket functions, so all systems may not support this yet. If it is unsupported by the system, an attempt to use this method will abort the program.

The atmark() functionality is also exportable as sockatmark() func-

tion:

use IO::Socket 'sockatmark';

This allows for a more traditional use of sockatmark() as a proce-

dural socket function. If your system does not support sockat-

mark(), the "use" declaration will fail at compile time. connected If the socket is in a connected state the peer address is returned. If the socket is not in a connected state then undef will be returned. protocol Returns the numerical number for the protocol being used on the socket, if known. If the protocol is unknown, as with an AFUNIX socket, zero is returned. sockdomain

Returns the numerical number for the socket domain type. For exam-

ple, for an AFINET socket the value of &AFINET will be returned. sockopt(OPT [, VAL]) Unified method to both set and get options in the SOLSOCKET level. If called with one argument then getsockopt is called, otherwise setsockopt is called. socktype Returns the numerical number for the socket type. For example, for a SOCKSTREAM socket the value of &SOCKSTREAM will be returned. timeout([VAL]) Set or get the timeout value associated with this socket. If called without any arguments then the current setting is returned. If

called with an argument the current setting is changed and the pre-

vious value returned.

Socket, IO::Handle, IO::Socket::INET, IO::Socket::UNIX

AUTHOR Graham Barr. atmark() by Lincoln Stein. Currently maintained by the

Perl Porters. Please report all bugs to .

reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. The atmark() implementation: Copyright 2001, Lincoln Stein . This module is distributed under the same terms as Perl itself. Feel free to use, modify and redistribute it as long as you retain the correct attribution.